As the retail landscape evolves, the drive for sustainability and efficiency has never been more pressing. Supermarkets, in particular, are at the forefront of this transition, embracing innovative technologies to strengthen their energy management strategies. Among these innovations, real-time energy management systems, especially when integrated with solar PV solutions, are emerging as a true game changer.
Hark Systems, an energy analytics and industrial IoT company owned by SolarEdge, has worked with leading UK retailers including Sainsbury’s and Asda to analyse and optimise their energy use, buildings and industrial assets. In this feature, Hark Systems’ CEO Jordan Appleson discusses the benefits, challenges and transformative potential of real-time energy management in the supermarket sector
The supermarket industry is characterised by intense competition and slim margins. In this environment, optimising efficiency across every part of the business, from the supply chain through to onsite energy use, is critical.
Industry data shows that UK supermarkets currently account for approximately three percent of the country’s total electricity consumption. However, with the retail sector undergoing rapid digitisation and electrification, this demand is expected to surge in the coming years. A key challenge facing supermarkets will be meeting the growing demand for electric vehicle (EV) charging, both for commercial fleets and customer vehicles – a significant and costly energy load which will further escalate power requirements.
Of course, rising energy use, and therefore rising energy costs, is not the only issue keeping energy and facilities managers in the retail sector awake at night. They also need to balance these increases with ambitious carbon reduction goals.
Understanding the energy fow
To meet increasing energy demands, many supermarket operators are adopting renewable energy solutions to power their facilities with clean, low-cost energy, with solar PV emerging as a leading choice. Supermarkets, with their expansive, unobstructed flat roofs, provide the perfect canvas for large-scale solar arrays. By harnessing solar energy during peak shopping hours, retailers can significantly reduce their reliance on grid energy, leading to lower electricity bills. Additionally, by integrating a battery storage system, excess solar energy can be stored for use during off-peak hours or after sunset – improving self-consumption and keeping essential appliances powered by clean, low-cost energy around the clock.
Advancements in solar technology, especially solar inverters using module-level power electronics (MLPE), are already unlocking powerful new opportunities for retailers to optimise solar energy production and usage. These innovations are driving higher energy yields, enabling greater cost savings, and reducing operations and maintenance (O&M) expenses through advanced monitoring capabilities.
But maximising solar energy production is only part of the picture. To fully unlock its value, retailers must also manage how and when that energy is used, and this is where smart energy management comes into play. By combining real-time data from onsite solar PV systems and energy-consuming assets such as freezers, lighting and EV chargers, retailers can gain a complete, data-driven view of their energy consumption. These insights can then be turned into strategic actions that streamline operations, reduce waste, and unlock further cost savings.
Energy management on the edge
In an industry such as retail, achieving the cross-category approach to energy management proposed here is not without challenges. What is required is a “single pane of glass” – a unified platform through which retailers can monitor and control energy production and consumption across their entire estate in real time. This can require installing thousands of sensors across diverse assets such as bakery ovens, freezer cabinets, lighting, HVAC, EV charging points, and more. To support such an extensive hardware setup, an edge-based computing system must also be deployed to process millions of sensor readings in real-time, enabling visualisation, exploration and analysis of the data. Installing this infrastructure can be a significant undertaking even for a single store. When scaled across an entire network of stores, warehouses and logistics centres, the scope becomes even more substantial. However, the benefits of such an approach can be both rapid and transformative.
A success story: Sainsbury’s
In 2017, Hark Systems partnered with Sainsbury’s to improve visibility and control of energy consumption across key asset groups, supporting the retailer’s goal to reach net zero emissions by 2040. Working closely with Sainsbury’s, the Hark team identified energy-intensive assets and conducted an on-site survey to connect them to the Hark Connect platform. A proof of concept was then deployed in a single store, monitoring multiple asset groups, including bakery ovens, refrigeration units, HVAC systems, and lighting.
The initial energy monitoring highlighted errors in energy consumption processes that were the leading causes of high usage. For example, a malfunctioning asset was identified as being responsible for excessive energy draw, enabling Sainsbury’s to take corrective action and prevent further losses.
Following the success of the initial trial, Sainsbury’s scaled the Hark platform to more than 600 stores. Today, the retailer receives over 368 million energy readings daily across 40 different asset groups. This centralised system enables Sainsbury’s HQ to monitor all connected stores and devices, identify inefficiencies, remotely control energy usage, and anticipate potential asset failures before they occur.
In terms of bottom-line impact, Sainsbury’s has reported a 4.5% reduction in lighting costs alone. For large retailers, a 4.5% annual saving can translate into millions of pounds.
Switching on new revenue streams
The impressive results achieved by Sainsbury’s, and the many other leading UK supermarkets Hark Systems works with, highlight the real, measurable benefits of investing in real-time energy management. While the return on investment varies by use case, it’s possible for retailers to see a return of £3 to £4 for every £1 spent on advanced monitoring solutions within just a year, making the financial case clear cut.
The business case for real-time energy management becomes even more compelling when we consider the transformation underway in the retail electricity market. We are entering a new era of flexible energy pricing, presenting exciting opportunities for enhanced energy efficiency and optimisation. Real-time monitoring enables retailers to navigate this shift effectively, allowing them to capitalise on favourable pricing changes and avoid potential penalties.
In a flexible pricing market, time-of-use (ToU) pricing strategies become incredibly important. Armed with a complete picture of energy consumption patterns across their stores, retailers can make smarter decisions about when and how to use energy.
For example, if a solar and battery system is in place, excess solar energy generated during the day can be used to pre-cool freezer units. This allows freezers to be turned off for an hour or two after sunset – when solar production drops and grid electricity prices typically peak – reducing costs without compromising the integrity of stored perishable goods. Additionally, by using excess energy in this way, businesses can avoid violating grid export regulations, which limit how much energy can be exported to the grid. This is important as exceeding these limits can result in hefty fines.
The evolving energy landscape also presents opportunities for retailers to engage in energy arbitrage – storing solar energy or buying and storing energy from the grid when prices are low and then selling it back when prices rise. At this point, the focus shifts from simply saving money to generating revenue, an attractive prospect for any business. By ingesting market operator data and tariff feeds and combining them with on-site energy information, real-time management systems enable intelligent energy trading. This enhances decision-making by enabling retailers to monitor market conditions and energy prices in real time and automatically buy and sell energy when trading conditions are more favourable.
While this process is still at an early stage, it’s important for businesses to proactively consider their energy strategies, particularly when planning new onsite generation assets. For example, I think we’ll begin to see more commercial operators intentionally oversize solar PV systems to produce more energy than they need in order to take full advantage of energy trading opportunities.
Sustainable and efficient retail operations
The integration of real-time energy visibility within the supermarket sector is not just a technological advancement; it represents a vital shift towards more sustainable and efficient retail operations. As highlighted by Sainsbury’s successful implementation of a real-time energy management system, the potential benefits are significant – ranging from substantial cost savings and enhanced operational resilience to compliance with both internal and external carbon reduction goals.
As retailers confront rising energy demands and a rapidly shifting market landscape, the ability to monitor and manage energy consumption in real time will become essential. By leveraging innovations in solar technology and advanced analytics, supermarkets can optimise their energy use and engage in energy arbitrage, not only to meet current demands but also to position themselves for a more profitable and sustainable future.
This transformative journey is not without its challenges. However, with the right systems in place, supermarkets can position themselves as leaders in sustainability while navigating the complexities of a dynamic energy market.
